Immune response in infants after universal high-dose hepatitis B vaccination: A community-based study in Beijing, China

Background: Vaccination of infants beginning at birth is recommended to prevent Hepatitis B virus (HBV) infection in China. Compared to 5 mu g/dose vaccine administered in other regions in China, a three-dose HB recombinant yeast vaccine at 10 mu g/close has been administered for infants within 24h after birth, 1 month and 6 months of age in Beijing since 2006. In a community-based retrospective cohort study, factors influencing immunologic vaccine response were evaluated. Methods: A total of 3670 infants who completed a 3-dose 10 mu g recombinant HB vaccine regimen and born to hepatitis B antigen negative mothers were included. The effect on anti-HBs titers of maternal nutrient status, infants' birth condition, growth factors, timeliness of vaccination, dosing interval and the interval until post-vaccination serologic testing (PVST) were evaluated. Results: A total of 3666 infants with no markers of HBV infection were included in analysis. The mean anti-HB titers were 1767.17 mIU/ml. Only 16.9% of the infants completed their PVST within 30-59 days after the final dose of vaccination. Multivariate linear regression analysis showed that delay in PVST (beta = -0.097, p < 0.0001) and maternal folic acid supplementation (beta = 0.067, p = 0.002) were associated with log-transformed anti-HB titers. Also a trend toward significant association was observed between the calcium supplementation of infants and log-transformed anti-HBs titers (beta = 0.062,p = 0.057). Longer interval between dose 2 and dose 3 was not observed to increase the anti-HB titers after cofactors adjustment. Conclusions: Our findings illustrate the importance of timing of PVST to avoid unnecessary revaccinadon. Multi-center large cohort studies should verify the effect and magnitude of folate and calcium supplementation on HB vaccine response. (C) 2015 Elsevier Ltd. All rights reserved.